hey
i have a 95 mk6 escort, 1.6 efi. when you rev the engine up,then let the revs off again theres a gurgling or hissing noise comin from a grey box that attatches to the outlet manifold by a series of copper pipes, im not a mechanic as you can probably tell but i was maybe thinking that the problem may be down to a blockage in the exhaust? causing some of the exhaust fumes to escape through the small valve in this grey box? is it a saftey measure to stop back pressure building up in the engine, if so how can i resolve this problem, my cars not going as fast as it once did, just wondering if this is what has caused it.
regards
andy